The number system children will use throughout their lives is based on a place-value system. Understanding the place value system is a foundation to all operations as children progress in… More →

During recess, friends learn about place value by working together to add and subtract by tens on the playground at school. More →

Class 301 has won a real truckload of number cubes. Fractions Frank, the caretaker, has found some boxes that hold different amounts of cubes--ones, tens, hundreds, and thousands. The… More →

Have you ever built something really big with building blocks? Did you need to use hundreds of blocks? Read about an after-school center, where the toys are counted in ones, tens, and… More →

This gripping title traces the causes, symptoms, and treatment of plague through the height of the Black Death in Europe and into the modern day. More →

From the mysterious plagues and diseases of ancient times to global epidemics and the flu, these disasters have evoked fear in the hearts of people. This book looks at types of diseases, how… More →

Scientists use different kinds of investigations depending on the questions they are trying to answer. Accessible text and child-centered examples guide readers as they learn to plan simple… More →

Kids love machines that fly! This amazing book explains the basics of how planes and helicopters work. Topics include engines, wings, propellers, fuel, and flying safety. A quiz at the end… More →

In this book, you'll find out where planes go and how people use them. More →

Earthquakes, volcanoes, fossils, and gemstones - kids will want to put what they learn about our planet into action with exciting art activities. Fascinating activities will help make the… More →